Draft gear



H. BARNARD E'T AL Feb. 9, 1932.

DRAFT GEAR Filed Sept. l5, 1923 4 Sheets-Sheet l f2@ V02? anstv NN w Feb. 9,193.2, H. BARNARD ET AL DRAFT GEAR Filed sept. 15, 192s" 4 sheets-shea 2 Feb. 9, 1932. H. BARNARD r-:T AL 1,844,238

DRAFT GEAR Filed Sept. l5, 1923 4 Sheets-Sheet 3 Feb. 9, 1932. H. BARNARD ET AL DRAFT GEAR 4 sheets-smet 4 Filed Sept. l5, 1923 [mwen am- Patented Feb. 9, 1932 narran s'rA'rEs rar dic HARRY BARNARD AND WALTER COTTON, OF CHICAGO, ILLINOIS, ASSIGNORS' -TO 'UNION DRAFT' GEAR COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 0F DELA- WARE DRAFT GEAR Application' med september The invention relates to draft gears or shock absorbing devices for railway cars; itsV object being to secure a high degree offefficiency and smoothness of action.

The inv-ention consists of a structure such as is hereinafter described and is illustrated in the accompanying drawings, in which Fig. 1 is a central plan section of the gear, the draft sills of a car being shown in detail;

F ig. 2 is a sectional view of the gear on the line 2-2 of F ig. 1; Y v

Fig. 3 is a. view similar to Fig. 1, the gear being under compression;

Fig. #lis a sectional View of the gear on the line -el of Fig. 3;

Figa' is a View in perspective -of a frictional shoes used i-n the gear;

TEig. 6 is a vertical central longitudinal section of the gear; v

Fig. 7 is a sectional viewtake on the line 7-7ofl`ig.6; l i

Fig. 8 is a view similar to Fig. 1, showing a modified vform of construction;

Fig. 9 is a detail of one of the followers partly broken awayand partly in seetion,and showing a modified form of friction plates; and

F ig. 10 is a detail shoes of Fig. 8.

A pair of center or draft sills of a railway car is showny at 10, 10, and as being provided with a pair ef draft lugs 11, 11, anda pair of bulli-ng lugs 12, 12. The draw-bar of a coupling device is shown at 13, and its eXtenpair of of one of they wedging sion or yoke is represented at 111 and is `of ordinary kloop form for inclosing'the draft gear proper.

The improved gear comprises a pair-of box form .or chambered followers, the forward follower being designated 16 and the rearward follower 17. These' two followers are preferably of like construction, each comprising an end plate or wall which engages the draft or buiiing lugs, and top, bottom and side walls of such length that when thegear is compressed to its full extent, as shown in F ig. 3, thewalls of the two followers meet and form a positive stop. 4 I

The end walls ofthe followers are shown as being centrally recessed to accommodate :the

15, 1923. Serial No. 662,815.

head and nut of a retaining bolt 18, which eX- tends centrally through the gear and serves as means for holding the various elements thereof in assembled relation pending the in stallation upon a car. y

Seated. against the inner face of the end wall of each Aof the followers is a wedge-block or `element 19, 19, its wedging faces being vertical and inclined inwardly, and adapted to exert outward pressure.

A releasing spring 20, of helical form, reacts between the wedge elements 19, 19, its principal function being to insure a return of the various parts of the gear to normal position after compression, though serving also as a resistance element when compressing stresses are applied ,in either direction. A pair of shoes 21 21, cooperates with the wedging faces of vthe element 19 associated with the forward follower, and a similar pair of shoes 22, 22, cooperates with the wedge ele-` ment 19 associated with the rearward follower.y The cooperating inclined faces of the blocks 21, 22, and of the elements .19, 19, are, of course, disposed at the same angle to the axis of the gear.

The longitudinal inner faces.7 as 23, .of the shoes 21, 22, are inclined in the opposite direction from the outer faces',-but preferably, as shown, at a wider angle to the aXis of the gear. Against the inner faces of each pair of shoes there bears a spring seat 24, 24, and between these two seats there reacts a more powerful helical spring 25, the function of which is to resist the relative approach of the two pairs of shoes as either of the wedging elements'19, 19, is advanced, and thus insure a lateral movement of the shoes.

The base or outer faces of the several shoes 21, 22, are preferably somewhat elongated and frictionally engage the inner faces of a pair of wedging plates 26, 26, .the 'inner faces of which are inclined inwardly from their ends providing a series of long and quite acute wedging surfaces.

Interposed between each of the plates 26 and the adjacent side walls or casings of the followers 16, 17, is a group of thin intercalating friction plates. Each of the groups of friction plates is made up of two sets 27, 28

icc

the length of these plates being preferably slightly less than the distance between the inner faces of the two followers 16, 17, when the gear is fully compressed, as in Fig. 3. The plates of one set, as 27, extend normally from a short distance from the inner face of the forward follower, and the other set of plates 28 extend normally7 from a short distance from the inner face of the rearward follower.

Each of the plates of the set designated 27 is recessed in its edges to receive retracting ribs 29 and 30, formed, respectively, across the top and bottom walls of the follower 16, the recess exceeding the width ofthe rib to as great an extent as the normal spacing between the ends of the plates and the end wall of the follower. rAdjacent the farther ends of the plates 27 their side margins are cut away to provide clearance for similar ribs on the top and bottom walls of the follower 17 In like manner theplates 28 are recessed to receive retracting ribs 31, 32, formed on the top and bottom walls of the follower 17, and at their farther ends are cut away, as shown at 82, to provide clearance for the ribs 29, 30.

In assembling the gear the` two sets of the plates forming each group of plates are differently arranged. ln one group one of the plates, 27, is in engagement with a plate 26, and one of the plates of the set 28 is in engagement with the side walls of the followers. In the other group one of the plates 27 is in engagement with the side walls of the followers, and one of the plates of the set 28 is in engagement with the adjacent plate 26.

Normally the various parts of the gear are in the positions shown in Fig. 1. Upon the compression of the gear by a buffing action the follower 16 ismoved baclrwardly, carrying with it the wed'ging element 19 which tends to advance the shoes 21, compressing both of the springs. The advance movement of shoes 21 is resisted by the spring 25, and these shoes are consequently forced outwardly by a wedging action, compressing the friction lates 27 28, between the plates 26 and the side walls of theifollowers. The pressure of the spring 25 upon the shoes 22 causes them to slide upon the wedging faces of the inner element 19, forcing them outwardly and .simi larly compressing the plates 27 28, between theV plates 26 and the side walls of the follower 17 As the shoes 21 move inwardly they slide. upon the inclined inner faces of the pla-tes 26, but because of their frictional engagement therewith carry these shoes forwardly to some extent and ultimately to the position shown in Fig. 3.

At the commencement of the inward movement of either of the followers the shoes 21 or 22 which are associated with the follower which is set in motion are urged forwardly and outwardly by the wedge-block 19. The forward. the spring 25 against the shoes, as 22, at the the movement of the shoes compresses Y opposite end of the gear, causing them to move backwardly, and, under the influence of the wedge-block 19 with which they are engaged, they are caused to move outwardly.

The outward movementV of the several shoes 21, 22, compresses both groups of friction plates. lVhen these groups of plates have been fully compressed, that is to say, when the slack has been entirely taken up,

' the continued advance of the moving follower causes the shoes inclosed within it to slide along the faces of the plates 26, 26. As these faces converge toward the middleof the gear the shoes are necessarily forced inwardly by their wedging action. This inward movement of the shoes causes their wedging faces which are engaged with the wedging faces of the block 19 to slide inwardly upon the latter, which movement causes the shoes to advance more rapidly than the wedge-block 19. The inward movement ofthe shoes along the faces of the wedge-block, and their consequent more rapid forward movement, is made possible by tlie angular relation of the opposed wedging faces of the block 19 and wedging faces of the plates 26, the angle included between such opposed faces being greater than the angle of repose. As the shoes which are inclosed within the movingfollower advance,

the plates 26 are also urged forward by the friction developed between them and the shoes. This advance movement of the plates 26 urges the shoes, as 22, to the opposite end of the gear baclrwardly and wedges them inwardly. The inward movement of these shoes causes their wedging faces to slide upon the wedging faces of the block 19and hence movin the shoes baclrwardly toward the middle of the gear against the frictional resistance of the plates 26 and the pressure of the spring'25.

Upon the engagement by the end wall of the `follower 16 with their ends, the plates 27 are moved forwardly, carrying with them the plates 28 until the latter engage the end wall of the follower 17 ,Y their further advance causing them to slide between the plates 28 and upon one of the plates 26 and one of the side walls of the follower 17.

By reason of the reverse arrangement of the twosets of plates of the two groups, the tendency of the advancing plate, as 27, to urge forwardly the plate 26 with which it is engaged is counteracted by the retarding action of the inner plate, as 28, of the group at the opposite side of the gear upon the plate 26 with which itis, engaged. As the plates 26, 26, are interloclred (as hereinafter described) they are in effect aunit, and hence the forward urge at one side is counteracted by the retarding action at the opposite side, and the plates 26, 26, always remain approximately in central longitudinal position.

There isslidable frictional engagement between both ofthe wedging .elements 19 and 'f2 the shoes with which each* cooperates; between each of these shoes and the spring seat associated with it; between each of the shoes and one of the plates 26; between these plates and the adjacent friction plate; between the friction plates themselves and between the outer friction plate which is in movement and the side wall of the follower which is at rest.

lThe action of the. gear under the influence of pulling stresses is the same as in bui'ling, the parts, however, moving in the opposite direction.

Vhen the compressing pressure is relieved the various parts of the gear-are returnedV to the normal position, as shown in Fig. l; the release spring 20 moves baclwardly the wedging element 19, which has l,been advanced, and the follower with which it is associated. The spring 25 pushes backwardly the shoes which had been advanced, and, as its tension is reduced, pressure upon the other pair of shoes is relieved and they are per-Y mitted to slide inwardly upon the wedging faces of the element 19. The ribs 29, 30, or 31, 32, engage with the instanding shoulders of the friction plates with which they cooperate, and move them backwardly, thefrictional engagement between the plates insuring the return to normal position of the other set of friction plates and of the plate 26.

ln order that the two plates 26, 26, may ertainly move together under all circumstances, they are interlocked. This is accomplished by providing each with an instanding flange 33, 3l, and 35, 36, at each of its margins, as shown in Fig. 5, corresponding flanges of each of the plates having complementary lugs 37 and recesses 38.

As further means for insuring uniform movement of the two plates 26, 26, there may be used in place of the tension spring 25 two springs 39, 40, arranged in tandem and seating at their inner ends upon an instanding web 4l formed integral with the shoes, as shown in Fig. l0.

A gradual Ydevelopment of the frictional resistance of the gear may be secured by varying the length of the friction plates 0f each set, as shown in Fig. 9, so that the advancing follower will set these plates in inotion successively.

Vfhile preferred forms of construction are shown, various changes in the shape and arrangement of the parts may be made without departing from the scope of the invention, and when the maximum efficiency of which the gear is capable is not required some of its features may be dispensed with, as, for example, the wedge form of the plates 26. As the elements 19 have no movement relatively to the followers with which they are associated, they may, if desired, be formed integrally therewitl lVe claim as our invention- 1. In a draft gear, in combination, a pair of chambered followers, a double faced wedging element associated with each follower, a pair of laterally movable `friction shoes associated with each wedging element, spring means reacting between the two pairs of shoes, a pair of intercalating oating friction plates having inwardly wedging faces engaging the several shoes, a group of intercalating friction plates interposed between each side wall of the followers andthe adjacent floating friction plate, the two sets of plates forming each'group being directly associated one with each of thel followers, the order ofy arrangement of the plates of the two groups with respect to the side walls of the follower and the friction shoes being reversed.

2. ln a draft gear, in combination, a pair of chambered followers, a double faced wedging elementV associated with each follower, a pair of laterallvmovable friction shoes as'- sociated with each wedging element, spring means reacting between the two pairs of shoes, a group of intercalating friction plates interposed between each side wall of the followers and the adjacent friction shoes, the two sets of plates forming each group being directly associated one with each ofthe followers, and a wedging plate interposed between the two shoes ateach side of the gear and the contiguous group of plates, the two last-named plates being Vlocked together against independent longitudinal movement.

ln a draft gear, in combination, a pair of opposed casings, an outwardly wedging element within each casing, an inwardly wedging element common to both casings and reacting against the side walls thereof, said elements being tending flanges, means on one of said flanges for interlocking with the corresponding flange of the other elementa friction shoe interposed between each of the first-named wedging elements and theI inwardly wedging element, the angular relationV of the opposed wedging faces being .greater than the angle of repose, and spring means for restoring' the first-named wedging elements and the shoes to normal position after the compression kof the gear, means for resisting compression of said gear, and means for restoring the parts to normal positionafter compression. f

4. In a draft gear, a pair of opposed chambered followers, a group of intercalated friction plates within said followers kat each side of the longitudinal axis thereof, a double faced wedging element in frictional engagement with each group of plates. means for interlocking said to move together, and means comprising friction shoes and cooperating wedge members for moving said plates laterally upon the compression ofsaid gear. 4

V5, In a friction shock absorbing mechaprovided with inwardly eX- elements to cause the same n i-ic nism, the combination with front and rear main followers movable toward and away from each other; of a plurality of intercalated, relatively movable friction plates interposed between said followers, and adapted to be moved thereby, certain of said plates being normally spaced from one ofsaid followers and the remaining plates being spaced from thev other follower; friction elements co-operating with said plates, said elements being bracedfby longitudinally extending stiffening members; lateral pressure-creating means coacting with said friction elements; means for resisting lateral movement of said plates; and a spring resistance for said pressure-creating means.

6. In a friction shock absorbing mechanism, the combination with a friction shell; of two groups of relatively movable, intercalated friction plates coacting with the shell; means for effecting relative movement of said plates, said means being normally spaced from said plates; spreading` means between said groups of plates for placing the same under lateral pressure; a longitudinally disposed friction element interposed between said spreading means and each group of plates, each of said elements being provided with stiffening means.

7. In a friction shock absorbing mechanism, the combination with front and rear main followers movable toward and away from each other; of a friction shell interposed between said followers; a plurality of friction plates within the shell, said plates being adapted to be engaged and moved by said followers, said plates being divided into two groups at opposite sides of the mechanism and coacting with the side walls of the shell, the plates of each grou having their outer ends'normally spaced from said followers; a longitudinally disposed friction element coacting with each group of friction plates, each of said elements being provided with stiffening iianges; a longitudinally disposed spring Aresistance between said elements; and wedge-pressure-transmitting means at opposite ends of said spring resistance co-operating with said plates.

S. In a friction shock absorbing mechanism, the combination with front and rear main followers movable toward and away from each other; of a plurality of intercalated, relatively movable friction plates interposed between said followers, and adapted to be moved thereby, certain of said plates being normally spaced from one of said followers and the remaining plates being spaced from the other follower; kfriction elements cooperating with said plates, means for reinforcing said elements, lateral pressure-creating means comprising a plurality of wedge elements and friction shoes coacting with said friction elements,-means Yfor resisting lateral movement of said plates, and a spring resistance for said pressure-creating means.

9. In a draft gear, in combination, a pair of chambered followers, a. wedging element associated with each follower, a pair of laterally movable friction shoes associated with each wedging element, a group of intercalating friction plates located between each side wall of the followers and the shoes, the outer ends of said plates beingspaced from said followers in their normally released position, and engaging said followers upon compression lof said gear, the two sets of plates forming each group being directly associated one with each of the followers and movable therewith; a wedging plate interposed betweenthe two shoes at each side of the gear and the contiguous group of plates, a reinforcing flange extending longitudinally of each wedging plate, each ,of the wedging plates having an instanding spring seat intermediate of its ends, springs reacting between such seats and the shoes at each end of the gear, and a spring extending longitudinally of said gear and engaging said wedging elements for releasing the same upon release of the gear.

YHARRY BARNARD.

WALTER-H. COTTON. 

